1. Field
Various features relate to the out-of-service network acquisition for wireless mobile devices that have multiple transceivers.
2. Background
Wireless terminals typically comprise integrated semiconductor devices, which may also be referred to as integrated circuits (ICs), and which may include one or more processors, memories and modems used for wireless communications. An IC may be provided on a die in a package that includes one or more dice provided on a substrate, and some degree of electrical and thermal coupling exists between the dice. Each of the one or more dice may support a plurality of modems that operate independently, although some degree of interference may be experienced due to the close proximity of the modems and/or constituent components of the modems. For example, interference may be transmitted through parasitical capacitances and inductances and/or through electromagnetic coupling of conductive traces, including power and ground planes.
Interference can be problematic for wireless communication devices that support Dual-Subscriber Identity Module (SIM), Dual-Active (DSDA) modes of operation. In particular, during system selection and out-of-service (OOS) scans, one technology active in a DSDA device can produce interference that can desensitize the receiver of another technology used by the DSDA. A wireless device generally performs OOS scans for signals above a minimum power threshold, where the threshold determines whether a full-acquisition process is triggered. The minimum power threshold is generally based on signal and interference power levels anticipated in the air within a wireless coverage zone. The minimum power threshold can enable rapid service acquisition by single-active devices.
However, in DSDA devices, interference power between the technologies supported on the DSDA device can easily exceed the minimum power threshold, and may result in many false triggers and acquisition attempts. False triggers can degrade OOS power consumption by wireless devices. When DSDA devices follow conventional OOS scans and system acquisition processes, a modem of the DSDA device may select services that are afflicted by interference from another active technology in the device. This can lead to poor call performance, and, therefore, poor user experience.
Therefore, there is a need for an improved method for OOS scanning and system selection in DSDA devices.